Analysis of Container Failures in a Geologic Repository - Mathematical Modeling of Container Pitting

Abstract

Pitting corrosion in low-carbon steel canisters cannot be ruled out. Pitting of steel container in contact with aerated groundwater is modeled mathematically. The relatively slow diffusion rate of oxygen will control the rate of corrosion if the inward diffusion of the dissolved oxygen occurs to compensate the oxygen consumption at the cathode. Equation for time-dependent pit penetration is derived. The pit penetrate deep if the area ratio of the pit and the metal surface outside the pit is small.